<!doctype html>
<html>
  <head>
    <meta charset="utf-8">
    <title>Demo</title>
  </head>
  <body>
    <a href="http://jquery.com/">jQuery</a>
    <script src="d:\Downloads\Development\jquery-1.7.2.js"></script>
    <script>
        window.onload = function(){ alert("welcome"); }
         $(document).ready(function(){
           $("a").click(function(event){
     alert("As you can see, the link no longer took you to jquery.com");
     event.preventDefault();
           });
         });
    </script>
  </body>
</html>